1. Field of the Invention
The present invention relates to a cable clamp, and more particularly to a cable clamp used for the automatic processing and assembly of a mini coaxial cable.
2. Description of Related Art
The quality of signal transmission through cables has an important effect on the performance of computers. Mini coaxial cable has many advantages such as small size, high tensile strength, endurance, better electrical capability and strong EMI (Electro Magnetic Interference) protection etc. Therefore, the application of the mini coaxial cable becomes more and more wide, especially when high quality of signal transmission is required. For example, a bunch of mini coaxial cables are typically used for connecting the mainboard of a notebook computer with a Compact Disc driver or a soft disk driver and so on. FIGS. 1 and 2 illustrate a single mini coaxial cable 1 which usually includes: 1) a core 11 constituted by a plurality of conductors 111 made of metal material (generally copper alloy); 2) an inner insulator 12 enclosing the core 11 which is commonly made of Teflon; 3) a metal braid 13 covering the inner insulator 12; and 4) an outer insulator 14 usually made of plastic material such as PVC.
Electrical connection between the cores of common cables and corresponding terminals of a connector is typically achieved by means of IDC (Insulation Displacement Contact). The forked insulation displacement portion of the terminal can easily pierce the outer insulator around the core and thus electrically contact with the inner conductive core. However, the mini coaxial cables cannot use IDC to achieve electrical connection between the terminals of the connector and the cores 11 thereof. Because in an IDC manner, when the forked insulation displacement portions of the terminals pierce the outer insulators 14 and the inner insulators 12, the terminals electrically connect with the metal braids 13 and the cores 11 simultaneously so that short circuit happens. Thus, at present, only soldering is adopted to achieve electrical connection between the terminals of the connector and the cores 11 of the mini coaxial cable. Referring to FIG. 3, the soldering process is as follows: first peeling a portion of the outer insulator 14 to expose a certain length of the metal braid 13, separating the metal braid 13 and soldering the separated metal braid 13 to a grounding pad 21 of a circuit board 2 mounted in the electrical connector for electrically connecting with a corresponding grounding circuit; then peeling a certain length of the inner insulator 12 to expose the core 11; and finally soldering the conductors 111 of the core 11 to signal pads 22 of the circuit board 2 for electrically connecting with a corresponding signal circuit. The circuit board 2 further has a plurality of conductive pads 23 onto which the terminals of the connector are soldered. The conductive pads 23 respectively connect with the signal circuit or grounding circuit via traces, thereby realizing the electrical connection between the terminals of the electrical connector and the core 11 of the cable 1.
The conventional process of peeling the outer insulators 14 is carried out as follows: a plurality of mini coaxial cables is first juxtaposed on an organic board and fixed in position by an adhesive tape; then the outer insulator of each cable is manually cut out by using an L-shaped scissor. But such a manner is time-consuming, laborious and ineffective. Furthermore, the metal braids 13 and the cores 11 are easily snipped and the quality is thus poor.
At present, a laser cutter is used to peel the outer insulator 14, in other words, by means of the laser light instead of the edge of a knife. The cutting depth is precisely controlled by controlling the intensity and the moving speed of the laser light. Such a cutting method ensures good cutting quality and high precision. However, a small clamp is required not only clamping the cables during the course of cutting the outer insulators but also being applicable to the product line. When the laser cutter cuts the outer insulators 14, it is also required that the clamp should be able to press the circuit board 2 against its side wall to facilitate cutting of the outer insulators 14 in a position proximate to the circuit board 2, so that the next metal braid 13 separating step can be carried out sequentially. Due to these requirements, the design of a clamp used for automatic assembling of the mini coaxial cables is very difficult.
Accordingly, an object of the present invention is to provide a cable clamp having a small and simple configuration which can steadily clamp cables, load and unload the cables rapidly and precisely. The cable clamp acts as a carrier circulating cables on the product line, thereby increasing automatization degree of the cable assembly, saving time and manpower, as well as reducing the costs of manufacturing and assembly of cables.
In order to achieve the object set forth, a cable clamp in accordance with the present invention comprises a base, a clamping arm and a locking piece. The base defines a receiving recess at one longitudinal end thereof. The clamping arm comprises a pivotable section at one end thereof rotatably received in the receiving recess, a pressing section extending from the pivotable section, and a fixed section formed at the other end thereof. The pressing section is adapted to press a cable against an upper surface of the base. The locking piece is rotatably disposed on the base and bears against the fixed section of the clamping arm for securely retaining the clamping arm on the base.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the present embodiment when taken in conjunction with the accompanying drawings.